hayman



Patented oa. 13, 193,1

`imma. .1. annum, or ranxizmune, -wins'r vmemu srovnrnun Anuman mearebmm is, m7. serial n. maar. i

l My present invention relates to a st'ovepipe or similar structure made from/sheet material, provided with a seam capable of bemg. y locked and unlocked so that in the case of a' l stovepipe, lengths of pipe maybe readiy nested for shlpment and quickly and e c ienly locked into tubular form when desire Importantl objects of the invention consist Vl in providing a lock for the edge portions of such structures which may bereadily sepa-- rated when desired but which in the case of a stovepipe, will be smoke tight while in use, which cannot be accidentally separated,

which will not be wasteful in material, and

-Which'can be readily and cheaply manufac- Other objects will appear as the descrpition proceeds and with re erence to the accompanyin'g drawings, in which:

-F1g.v1 is a view of a pipe section embodyinmy invention.

ig. 2 is a sectional View along the `line 2-2 of Fig. 1. a l Iig. 3 is a detailed perspective view of the In thel embodiment illustrated, I have shown a pipe generally at 1 having one longitudinal edge portion bent back upon itself so as. to'produce a fold 2 and a separated thickness of materiall 3. Within this cavity' or channelithus formed, -the opposite vlongitudinal edge portion 4 of the plpe is adapted to vbe enclosed. y

In order to securely lock the two edge portions together, I provide, offset locks shown y at 5 and at 6 in the thickness 3 between the raw andlfoldededges thereof. The stamped out y rtions 6 are obviously produced before the old 2 is made. It is essential to 'an eiiicient lock, that these offset locks be made in a direction toward the longitudinal axis of the pipe or structure. In addition, it is highly desirable that the fold be made on the seam or inside of the structure, so that a' smooth exterior is presented and for other purposes.

` Offset locks in each edge portion are similarly located.

5 It will be seen that in the osetting operation, a raw or sharp edge l7 Y is produced and an offset portion 8 having gently sloping shoulders 9..

,When the edge portion 4 is slipped between fold 2 and the thickness 3, the offset lock 5 55 in the edge portion 4 forces the fold 2 and thickness 3 apart untilthe lock 5 springs into the lock 6. Whenthe parts assume these ositions they cannot be separated laterally cca-use of the inherent spring of the thick- 00 vness 3 and fold 2. They cannot be ypulled directlyV apart because the raw edges of each lock engage each other. l

Due tothe sloping shoulders 9 howeverfa slight ta of one edge of the pipe in a longitudina direction will cause one lock to ride out of its fellow and the two edge portions may then be pulled directly apart.

It is to be noted'that when the edge portions are locked, the thickness 3 being on the 70 inside of the pipe, upon further flexing toward the longitudinal axis, each offset lock tends to more completely enter its fellow. This makes accidentalseparatioxi impossible.

In a locked pipe of this type it is im erative that the diameter or circumference t ereof be accurate. It therefore4 follows that should it be found after manufacture that an error in size had been made, the pipemust be capable of adjustment rather than to discard the section. If such is the case with the pipe of this invention, a mere refolding will accomplish the desired endywithout in any manner disturbing the locks.

It will be seen that there is no waste mate- 85 rial in the pipe herein described, that by simple operations, a rigid, eilcient lock is secured, but which mayl be readily separated when desired. This is sometimes of paramount'importance such as when part of the equipment of tourists, cam rs or the like.

In lthe claims Where I re er to an edge portion, I intend such expression to cover that part-of the'structure lying adjacent the actual edge thereof.

From the description and drawings it will be apparent that the raw edge 7 of lock 6 is engaged by the offset l k 5. Therefore, in the claims where I ref to the lock 6, I intend this expression to include this essential 100 yraw ed e 7.` So that when I say en a each other, I intend it to cover the stance where the offset lock engages the raw j edge 7 of the lock 6, which edge 1s in fact a 5 part of said lock.

What I claim is:

1. A pipe section comprising a sheet of metal,l one longitudinal ed e portion thereof being bent upon itself to orm an enclosing channel, and adapted to receive the other longitudinal edge portion therein, similarly placed offset locks in each edge portion adapted to engage cach other.

2. A pipe section com rising a sheet of metal, one longitudinal e ge portion thereof being bent upon itself to form three thicknesses of material, two of which are on the longitudinal axis side of the pipe, an offset lock in the innermost thickness of material, the other longitudinal edge portion of the section being held between two thicknesses of the first mentioned edge portion, and provided with a similar ollset lock engaging the first mentioned offset lock.

3. A pipe section com rising a sheetl of metal, one longitudinal edge portion thereof being bent upon itself to form three thicknesses ofy material, an offset lock in one thickness forming a rawed e, the opposite longitudinal edge portion o said section being enclosed between two thicknesses of the first mentioned edge portion, and a similar offset lock in said edge portion engageable with the raw edge of Fthe first mentloned punched out lock. 4. VA pipef section com rising a sheet of metal, one longitudinal e ge portion thereof being bent upon itself to form three thicknesses of material, the opposite longitudinal edge portion bein enclosed between two of said thicknesses, o ,set locks on one edge portion engaging similarly shaped and positioned offset locks in the other edge portion, said locks having gently sloping end shoulders.

5. A lock of the character described, comprising a tubular structure having anv edge portion doubled upon itself to form three thicknesses of material, an offset lock projecting beyond the surfaceof the doubled over,

portion and inwardly toward the axis ofthe tubular object, and similarly placed similarly shaped offset lock in a cooperatin ed e portion of the tubular object seated 1n t e first mentioned punched out lock.

6. A lock of the character described comprising a tubular structure doubled' upon itself to form three thicknesses of material two-of which are on the axis side of the tube,

I the innermost thickness of 'the doubledportion having a raw and a folded edge, a cut in said portion between said edges forming. a raw locking edge, said tubular structure having a cooperatmg e portion ada ted to 5 lie and be enclosed ietween the oubled thicknesses, so that the innermost thickness of the doubled portion lies on the axis side of the cooperating edge portioniand an ofset lock in sald edge portion projecting toward the tubular axis,-said lock projectingthroughv the'innermost thickness o the dou led portion engaging the raw locking'edge and preventing separation of theparts.

7. A lock of the character described comprising a closed sheet metal structure, one edge portion of said sheet being doubled back and forth on itself to form three thicknesses of material two of which are on vthe inside of said structure, a lock between the edges of the innermost fold, said structure havin a cooperating edge portion ada ted to lie ang be enclosed between the doubledp thicknesses, a lock in the cooperatin edge portion pro'ecting toward the inside o the structure, sai lock projecting through the innermost fold and engaging the first mentioned lock toprevent separation of the structure edge portions. 'A

. 8. A pipe section of sheet metal, one longitudinal edge portion being bent upon itself l inwardly of the ipe to form an inner layer and an intermedlate la er connecting the inner layer with the outer layer, sald inner la er having an openingl therein, and the 'ot er longitudinal edge portion of the pipe lying between the inner and intermediate layers and having an offset lock upset therefrom back from its extreme edge leaving the latter intact, said lockV projecting through said openin engaging with its raw edge t e raw edge ofl the opening in the inner layer, substantially as described.

9. A pipe section according to claim 8 in which an offset wall is provided covering the opening in the inner layer and covering also the offset lock first mentioned. i

10. A pipe section according to claim 8 in which the offset lock has its raw edge so disposed as to extend at an angle across the raw edge of the opening with which it engages.

11. A pipe section according-to claim 8 in which the offset lock has its end portions at an inclination to the sheet material, so that by a relative movement of the lock lengthwise of theA joint separation of the lock from the opening can be effected. l

In testimony whereof, I aix m signature.

EBER J. HYMAN. 

